I too use it on firearms. It's a NLGI #2 GC-LB grease that is specifically marketed for wheel bearings by the manufacturer. Seems to be doing fine.
"*GC-LB Wide temperature grease for use in components such as bearings, chassis and universal joints in passenger cars, trucks and other vehicles under mild and
severe duty. This includes vehicles operated under frequent stop-and-go service (buses, taxis, urban police cars, etc.), or under severe braking service (trailer
towing, heavy loading, mountain driving, etc.) (see ASTM D4950)."
The "Project Farm" guy on YouTube did a testing review on grease, but didn't include Super Lube - I suggested he add that but I don't think it's happened yet. He does several tests including one that measures the grease's ability to protect from friction.